Go to Ethernet and in then configure choose Select Manually (Advanced) and try lowering or raising your Maximum Packet Size (MTU). Is yours at 1500? Is this laptop connecting with a wireless or wired connection to your network?

Sometimes the auto-negotiating process goed wrong. Make sure both sides are configured 100Mbit full duplex fixed.
If that is the case and still the connection is slow than try another cable._________________MAC MINI/1.42/1GB/100G/SD/AP/BT/N

I tried putting manually both side to 100Mbs and full duplex but not helping.
The cable I use s certified for giga ethernet and with same cable and same laptop I've got fast transfer with another PC...

I'm stuck with transfering big files via usb hard drive, but I'd prefer just putting the mac in the network and copy accross the cable, it is much better I think.

I tried:
- manually set both machine to 100basetx and full duplex. Connection is working, I can access to the internet via my ADSL modem connected to my PC. But speed of PC to MAC is 2% of 100Mbps and MAC to PC is 50% of 100Mbps (maybe Mac mini HD speed limit?)
- full automation and negotiation and used assitant on mac. same result as above, slow PC to MAC speed.

Can't think of anything wrong with the PC as I've got a desktop pc with win xp which transfer very fast on both directions (I haven't mesured though)

I used my backup partition and I am getting at last some decent speed!
But in this configuration, I am not sharing the internet over my private network...

On my main partition where I have speed issue, I am sharing the internet connection so that I can surf on my mac mini through my PC. Now it seems that the Mac is copying files at the speed or through (I can't explain) the internet speed connection!! Which is 2Mbps hence the slow speed. For some reason the Mac is not detecting the 100Mbps speed.

Not a network professionnal so I might be wrong, but it looks as it is my problem here.

I googled for help and tried to manually set the ethernet to 100t/bx thingy and full duplex but not better.

We have over 100 minis colocated. We have seen the ehternet auto setting cause trouble on a fairly random basis. Identical minis pluged into the same switch : 3 of them are fine, one of them drops to 10/single. Who know why? The work around is as described set it to : 100/Full . Of the first 100 minis we saw problems in 6 or 7 of them.

We have over 100 minis colocated. We have seen the ehternet auto setting cause trouble on a fairly random basis. Identical minis pluged into the same switch : 3 of them are fine, one of them drops to 10/single. Who know why? The work around is as described set it to : 100/Full . Of the first 100 minis we saw problems in 6 or 7 of them.

I googled for help and tried to manually set the ethernet to 100t/bx thingy and full duplex but not better.

We have over 100 minis colocated. We have seen the ehternet auto setting cause trouble on a fairly random basis. Identical minis pluged into the same switch : 3 of them are fine, one of them drops to 10/single. Who know why? The work around is as described set it to : 100/Full . Of the first 100 minis we saw problems in 6 or 7 of them.

I usually don't point out grammar errors, because I myself can't spell to save my life, but when you actually misspell a URL and it actually work (because it's actually misspelled in real life), it's kind of amusing